Fresh reboot

Use UFS at /boot/tmp: [Use HAMMER2 home showed the same issue]
-r-xr-xr-x  1 aly  aly  3332816 16-Sep-2026 10:30 /boot/tmp/cryptsetup.good
-r-xr-xr-x  1 aly  aly  3332816 16-Sep-2026 10:30 /boot/tmp/cryptsetup.t1

$ sudo /boot/tmp/cryptsetup.t1 -d /home/aly/luks.key luksOpen /dev/ad0s0 test
Segmentation fault

$ cp /boot/tmp/cryptsetup.good /boot/tmp/cryptsetup.t2
$ sudo /boot/tmp/cryptsetup.t2 -d /home/aly/luks.key luksOpen /dev/ad0s0 test
libdm /usr/src-2/lib/libdm/dm_task.c:288: error: ioctl failed: 9
Cannot initialize device-mapper. Is dm kernel module loaded?

$ md5 /boot/tmp/cryptsetup.*
MD5 (/boot/tmp/cryptsetup.good) = 839eef63bcfd59fefbddcd410506bbb3
MD5 (/boot/tmp/cryptsetup.t1) = 416233ed7372d338cf50f89c2dac609c
MD5 (/boot/tmp/cryptsetup.t2) = 839eef63bcfd59fefbddcd410506bbb3

$ ll /boot/tmp/cryptsetup.*
-r-xr-xr-x  1 aly  aly  3332816 16-Sep-2026 10:30 /boot/tmp/cryptsetup.good
-r-xr-xr-x  1 aly  aly  3332816 16-Sep-2026 10:30 /boot/tmp/cryptsetup.t1
-r-xr-xr-x  1 aly  aly  3332816 16-Sep-2026 10:33 /boot/tmp/cryptsetup.t2

----

$ uname -a
DragonFly dfly.liwt.net 6.5-DEVELOPMENT DragonFly v6.5.0.1653.g7b7fb9-DEVELOPMENT #9: Tue Sep  1 20:37:42 CST 2026     aly@dfly.liwt.net:/usr/obj/usr/src-2/sys/X86_64_GENERIC  x86_64